---
slug: 33-model-routing-ensembling
role: index
date: 2026-04-21
---

> **📅 Research snapshot as of 2026-04-21.** Provider pricing, free-tier availability, and model capabilities drift every quarter. The router reads `data/routing-table.json` and `data/model-registry.json` at runtime — treat those as source of truth. If this document disagrees with the registry, the registry wins.

# Category 33 — Model Routing Ensembling

LLM routing frameworks, confidence-based escalation, best-of-N parallel generation, Elo / A-B testing for model selection, async race-with-validation.

## Angles

| File | Topic |
|---|---|
| [`33a-llm-routing-frameworks.md`](./33a-llm-routing-frameworks.md) | LLM Routing Frameworks |
| [`33b-confidence-based-escalation.md`](./33b-confidence-based-escalation.md) | Confidence-Based Escalation |
| [`33c-best-of-n-parallel-generation.md`](./33c-best-of-n-parallel-generation.md) | Best-of-N Parallel Generation |
| [`33d-elo-ab-testing-model-selection.md`](./33d-elo-ab-testing-model-selection.md) | ELO and A/B Testing for Model Selection |
| [`33e-async-race-with-validation.md`](./33e-async-race-with-validation.md) | Async Race with Validation |

## Also in this folder

- [`SYNTHESIS.md`](./SYNTHESIS.md) — synthesized insights across angles

## Up one level

- [`../index.md`](../index.md) — master research index
- [`../SYNTHESIS.md`](../SYNTHESIS.md) — master synthesis
